1. Field of the Invention
The present invention relates to a process for producing an organic carbonate. More particularly, the present invention is concerned with a process for producing an organic carbonate efficiently from an organic hydroxy compound using a specified catalyst in the absence of oxygen.
2. Description of the Related Arts
Heretofore, in order to produce organic carbonates, various processes have been proposed. For example, as the process for producing aromatic organic carbonates, a process using alkali metals and alkaline earth metals, basic quaternary ammonium, quaternary phosphonium or tertiary sulfonium compounds, hydroxides of alkali metals or alkaline earth metals, salts of strong bases and weak organic acids, bases such as primary amines, secondary amines, tertiary amines, and palladium (Japanese Patent Publication No. 38143/1981) as the catalyst; a process using a catalyst comprising Pd and the base as mentioned above, an oxidizing agent (compounds of group IIIA, IVA, VA, VIA, IB, IIB, VIB, VIIB metals) (Japanese Patent Publication No. 38144/1981), a process using a catalyst comprising Pd and a base, oxidizing agent (Co, Mn) and a drying agent (Japanese Patent Publication No. 38145/1981); a process using a base and a VIII group metal in oxidized state of +1 (Ru, Rh, Pd, Os, Ir, Pt) as a catalyst (Japanese Patent Application Laid-Open No. 68747/1978); a process using a base and VIII metal as the catalyst in an anhydrous condition (Specification of U.S. Pat. No. 4,201,721); a process using a catalyst comprising a base and VIII metal, and an oxidizing agent (having a higher oxidization potential than VIII metal (Japanese Patent Application Laid-Open No. 135743/1979); a process using a catalyst comprising Pd and a base, oxidizing agent, phase-transfer agent and a drying agent (Japanese Patent Application Laid-Open No. 102539/1980); a process using a catalyst comprising a base and a VIII group metal, and an oxidizing agent (Specification of U.S. Pat. No. 4,349,485); a process using a catalyst comprising Pd, Mn, R.sub.4 N .sup.+ X.sup.- (R indicates an alkyl group and X indicates a halogen) and quinone (Japanese Patent Application Laid-Open No. 104564/1990); a process using a catalyst comprising Pd, Co, R.sub.4 N .sup.+ X.sup.- (R and X are as defined above) and quinone (Japanese Patent Application Laid-Open No. 142754/1990); a process using a catalyst comprising Pd, an alkali metal or an alkaline earth metal or onium iodide compound and zeolites (Japanese Patent Application Laid-Open No. 165551/1989) are mentioned. However, the above-mentioned processes for producing aromatic organic carbonates have a problem in that the yield was insufficient.
As the process for producing aliphatic organic carbonates, a process using Pd, Cu or Fe as the catalyst (Specification of U.S. Pat. No. 3,114,762); a process for producing divalent Cu ion (Japanese Patent Publication No. 11129/1970) are mentioned. These processes, however, have problems in that the rate of the catalytic reaction is low, and that a large amount of the catalyst is required. Further, according to these processes, the yield is insufficient.
On the other hand, as the carbonylation method using Pd component and quinone component, a process for producing oxalic diester using Pd (NO.sub.3).sub.2 and quinones as the catalyst (Japanese Patent Application Laid-Open No. 94338/1980); a process for producing oxalic diester using Pd, quinone and a redox agent (U.S. Pat. No. 4281174), a process for producing cinnamic acid ester using Pd, quinone and a redox agent (Japanese Patent Application Laid-Open No. 126152/1987); a process for producing dialkyl carbonate using Pt group, Cu and quinone (Japanese Patent Application Laid-Open No. 212305/1987) are mentioned. However, these carbonylation methods have many problems in that the kinds of the products to be produced are limited and that the yield of the desired product is not sufficient.